1. Field of Disclosure
The present disclosure relates to an improved method of and apparatus for laser scanning bar code symbols during bar code symbol reading operations.
2. Brief Overview of the State of the Art
In general, laser scanning devices have a nominal scan angle, which controls the length of the scan line along the depth of field of the laser scanner. Most laser scanning devices have only a single scan angle, which is satisfactory in applications characterized by a relatively small depth of field.
For laser scanners having a large depth of field, it is desirable to have multiple scan angles for several reasons. One reason is that a larger or smaller scan line can make scanning easier in certain applications. A second reason is that it is easier to see a smaller (or shorter) scanning beam, than a longer one, because a short scan line has a greater beam intensity than a long scan line. A third reason is that providing user control over the scan length of a laser scanning beam can assist in reading a selected bar code symbol among a menu of bar code symbols.
One technique for controlling the scan angle of a laser beam during scanner operation is disclosed in U.S. Pat. No. 5,250,791 to Frederic Heiman et al (assigned to Symbol Technologies, Inc.) involves using a microcontroller to modify a laser scanning beam (i.e. scan or sweep angles) during operation. This solution, while useful, requires configuration (i.e. setup) of the scanning device before operation, and maintenance of the configuration settings during the lifetime of the device.
Thus, there is a great need in the art for an improved method of controlling the scan sweep angle of the laser scanning beam during scanning operations, while avoiding the shortcomings and drawbacks of prior art methods and apparatus.